[2:128] Our Lord! and make us both submissive to Thee and (raise) from our offspring a nation submitting to Thee, and show us our ways of devotion and turn to us (mercifully), surely Thou art the Oft-returning (to mercy), the Merciful. [2:129] Our Lord! and raise up in them a Messenger from among them who shall recite to them Thy communications and teach them the Book and the wisdom, and purify them; surely Thou art the Mighty, the Wise.
DD, we believe that there was continuity of 'guides' between Ismail (as) and our Prophet (as). Before our Prophet (saww), we find his his grandfather Abdul Muttalib (as) (leader of Quraysh at the time of event of 'Feel' mentioned in the Quran) and before Abdul Muttalib (as), there were others like Hashim, Abd Manaf etc. I suggest you read the history of the ancestors of our Prophet (saww) in the light of Sura Al Baqarah, particularly verses 120 or so onwards and ponder/research on the topic.
Now thats something new to me, are you saying that Abdul Muttalib and Abu Talib were Imams??????
As for the verse, the first says that promised messenger will be among offsprings of Ibrahim a.s while "among them" in second verse, i dunno what exactly are you implying from it.